email relaying
I'm running a server with Windows Server 2003 Web Edition and it's got IIS 6.0 on it. I think a remote computer somewhere is using my server to relay spam emails. Every few days I get 20 to 30 spam emails all from the same source - the sender is consistently postmaster@fmshah-server.telusplanet.net and the subject is consistently "Delivery Status Notification (failure)". I've setup my server to prevent relays from being sent from anyone except the localhost. I went into IIS and opened the properties of the Default SMTP Virtual Server, and went to Access -> relay -> checked "Only the list below" -> added 127.0.0.1 to the list -> unchecked "Allow all computers which successfully authenticate to relay, regardless of the list above". Under Messages, I have my email address in the "Send copy of Non-Delivery Report to:" field.
So if I'm getting tons of these "non-delivery" email in my inbox, does that mean my server is still allowing relays somehow - or would it send me "non-delivery" message even when someone tries but fails.
